How Much Is Too Much? Calculating Your Pet’s Daily Food Needs

Dogs may have different opinions about how much food is the right amount. photo AdobeStock

How much should I feed my pet? While most food packaging provides suggested amounts based on your pet’s weight, there are still some important considerations owners need to factor into the calculations. Don’t be put off by the scary math and science - this article will help you figure it out!

What’s the heck’s an RER? The first thing to know is your pet’s RER or Resting Energy Requirement. This is the amount of calories your pet needs to perform their involuntary physiological functions of digestion, respiration, heart and brain functions - in other words, the basic life-support functions they’d need if they never moved off the couch. To calculate your pet’s RER, take their weight and multiply it in kilograms raised by the ¾ power by 70. Or, if you’re like me and have no idea what that means, you can use this handy calculator: Ohio State University Basic Calorie Calculator.

Okay, but how do I get to total daily energy needs? Once you have your pet’s base RER number, you’ll need to factor in other considerations such as age, reproductive status, activity level, overall health, and whether they are over or underweight. Each of these factors is assigned a number, which you then multiply by the RER to estimate the animal’s total daily energy needs - in other words, the energy needed to sustain all the other fun things your furry pal does once he’s off the couch and running around. While this number will still only provide a rough estimate of your specific pet’s needs, it’s a good starting point. 

Here are some examples of how specific physical considerations change the RER and provide the total daily energy needs. Again, don’t fret. You can click here to see a complete list and have the confusing math done for you.

Neutered Male = 1.6% X RER
Inactive/Obese prone = 1.2-1.4% X RER
Weight loss diet = 1.0 X RER for ideal weight

The Ohio State Calculator at the above link will get you to a pretty decent baseline for your pet’s energy needs. Still, there are some other things to keep in mind so you can adjust your pet’s intake accordingly. In addition to the physiological and physical state of your pet, you’ll want to stay aware of their muscle mass and weight throughout their lives and adjust their food intake, as needed. If our pets gain or lose weight, we need to decrease or increase their calorie intake accordingly, just as we humans do when we notice our jeans are getting too tight (or wish we did!).

You’ll also want to be aware that many pet food labels are a bit off in their suggested food  portions because they are not factoring in the amount of fillers and additives combined with the essential nutrients such as proteins and amino acids. Take a look at the ingredient list on your pet’s food or treats; if it is primarily sugars, undefined ingredients, or other empty fillers, you’ll want to reduce the amount of that food they’re getting and add in some extra protein. 

Why is protein important? Our pets use protein to make nitrogen and amino acids that are essential to all living things. So, while energy requirements may vary, as discussed above, protein needs are somewhat static. Adult dogs need at least 1 gram of protein per pound of weight per day, while adult cats need at least 2 grams per pound (yes, amazingly cats require more protein per pound of weight than either dogs or humans). 

What about treats? Treats are often the most calorie dense food that we give our pets. Unfortunately, they are also the most likely to be filled with junk food ingredients. I personally use a lot of small cubes of sharp cheddar cheese in my training and my own pet treat giving, but cheese is still a calorie-dense food that does not contain as much protein as other foods created specifically for pets. 

In almost every training session, clients ask me how many treats they should give their dogs. According to the World Small Animal Veterinary Association (WSAVA), “daily treat intake should not exceed 10% of a dog’s energy needs.” How to achieve this? One simple way is to look at your pet’s regular food calories and reduce what you are giving them by 10%. Also, consider using shredded chicken or other clean protein as treats to help your dog get the protein needed. For an excellent article on the best treat amounts for both dogs and cats, check out this ScienceDaily article, which also includes a comprehensive RER chart.

Finally, remember that we can easily give our pets too many calories, but the estimates for recommended protein intake always say “at least.” This means calories from protein are always the best source, so using protein sources as your treats can help. 

Still, everyone deserves a little yummy junk food from time to time. As long as you’re staying within the 10% treat guidelines and your pup is getting enough protein, it’s fine to indulge your furry family member now and then - in moderation, of course!